Objective To summarize the clinical experience of extracorporeal membrane oxygenation (ECMO) treatment for adult acute respiratory distress syndrome (ARDS) caused by lung infections,so as to explore the clinical efficacy and application value of ECMO.Methods The patients with 7 ARDS who were responded poorly to mechanical ventilation in Zhongshan Affiliated Hospital of Sun Yat-sen University from January 2003 to January 2015 were collected.All patients were divided into a study group (7 cases) treated by ECMO and a control group (7 cases) treated by traditional methods.The percutaneous incision on femoral vein-internal jugular vein (V-V) was selected to carry out ECMO intubation,and the V-V ECMO model was used for auxiliary bypass of flow.The comparisons between the two groups for the results of hemodynamics,blood-gas analysis and oxygen metabolism were performed to evaluate synthetically the adjuvant effects of ECMO.Results Seven ARDS patients caused by lung infections were treated by ECMO,including 4 cases with bacterial pneumonia,2 cases with H7N9 and 1 case with H1N1.Thc duration of ECMO was (21.00 ± 10.06) days;2 cases were weaned from ECMO successfully,and 1 case recovered and discharged.Seven cases with ARDS caused by severe lung bacterial infections in control group were all not recovered on discharge.After treatment,the heart rate (HR),pulmonary arterial wedge pressure (PCWP),venous partial pressure of oxygen (PvO2),arterial blood lactic acid (Lac) in study group were significantly lower than those in the control group [HR (bpm)was 100± 12 vs.120± 19,PCWP (mmHg,1 mmHg =0.133 kPa) was 8.8 ± 2.6 vs.11.6± 3.8,PvCO2 (mmHg) was 40.8 ± 13.1 vs.48.9 ± 16.2,Lac (mmol/L) was 2.1 ± 0.8 vs.5.2 ± 0.6,all P ＜ 0.05],the mean arterial pressure (MAP),cardiac output index (CI),arterial and venous blood pH values,arterial partial pressure of oxygen (PaO2),arterial partial pressure carbon dioxide (PaCO2),arterial oxygen saturation (SaO2),oxygen delivery (DO2),oxygen consumption (VO2),oxygen extraction (ERO2) were obviously higher in study group than those control group [MAP (mmHg) was 83.6 ± 8.2 vs.72.2 ± 94,CI (mL· s-1 · m-2) was 93.35 ± 3.33 vs.81.68 ± 8.33,pH of arterial blood was 7.4 ± 0.1 vs.7.1 ± 0.3,PaO2 (mmHg):98.5 ± 20.4 vs.49.3 ± 12.6,PaCO2 (mmHg):38.9 ± 16.2 vs.26.1 ± 17.4,SaO2:0.95 ± 0.02 vs.0.58 ± 0.04,pit of venous blood was 7.1 ± 0.2 vs.6.4 ± 0.3,PvCO2 (mmHg) was 40.8 ± 13.1 vs.48.9 ± 16.2,SvO2 was 0.75 ± 0.07 vs.0.49 ± 0.08,DO2 (mL· min-1 · m-2) was 651 ± 36 vs.400 ± 81,VO2 (mL· min-1 · m-2) was 245.0 ± 11.2 vs.103.0 ± 14.8,ERO2 was (35.6± 3.9)％ vs.(21.3± 5.2)％,all P ＜ 0.05].Conclusions ECMO can improve hypoxemia.So it can improve the metabolism and maintain hemodynamic stability,in the mean time the patients may gain more time for diagnosis and treatment of their primary lung diseases.The key points of a successful ECMO are suitable selection of patients and forceful prevention of complications.

A female patient, years of age 56, having no distinct inducement before 5 d but developed fever, coughing, and shortness of breath, presented in People′s Hospital of Zhongshan with community-acquired pneumonia on March 3rd, 2023. Influenza A virus infection was confirmed on March 11th after performing macro transcriptome sequencing with alveolar lavage fluid, and H3N8 was confirmed with influenza typing afterward, having declared dead on March 16th. This case is a patient with refractory multiple myeloma autologous stem cell transplantation and continuous chemotherapy with immune dysfunction. She has a history of chronic upper respiratory tract infection. Imaging showed a widespread distribution of plaques, solid lesions, and other pneumonia manifestations in both lungs, a severe decrease in the counts of white blood cells, platelets, neutrophils, and lymphocytes, and a significant increase in laboratory inflammation indicators. After the clinical consideration was an acute aggravation of chronic respiratory tract infection and poor effect of anti-bacterial treatment, fungal infection was considered, and antibiotic treatment was changed several times according to the condition. Still, the outcome was poor, and the disease progressed rapidly. Medical workers initiated Oseltamivir antiviral therapy immediately after the alveolar lavage fluid etiology confirmed A-H3N8 influenza. However, due to complex and varied systemic symptoms, including inflammatory storm, sepsis, acute respiratory failure, tachycardia, coagulopathy, and other extrapulmonary organ injuries, she died 19 days after signs due to severe respiratory failure and multiple organ failure.

Human infection with avian influenza A (H7N9) is easy to induce severe acute respiratory distress syndrome (ARDS), and traditional mechanical ventilation cannot correct hypoxemia, so patients may die from multiple organ failure (MOF) caused by persistent hypoxia. Extracorporeal membrane oxygenation (ECMO) can provide effective respiratory support and win time for the treatment of severe H7N9. The first case of severe H7N9 in Guangdong Province in 2018 was admitted to Zhongshan Hospital Affiliated to Sun Yat-sen University. The case was insult with severe ARDS caused by H7N9, the traditional mechanical ventilation could not correct hypoxemia, and the lung condition gradually improved with ECMO assistance. After 13 days of ECMO support, the patient was successfully weaned from ECMO and was transferred to a general ward after 55 days. After 102 days of rehabilitation, the patient was discharged from hospital and followed up for 2 months, who was in good health and had a good quality of life. This article states the diagnosis and treatment of severe H7N9 in details, providing experience for the treatment of severe H7N9 in the future.